app/src/main/java/com/stoutner/privacybrowser/activities/ImportExportActivity.java

   1 /*
   2  * Copyright © 2018-2019 Soren Stoutner <soren@stoutner.com>.
   3  *
   4  * This file is part of Privacy Browser <https://www.stoutner.com/privacy-browser>.
   5  *
   6  * Privacy Browser is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Privacy Browser is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with Privacy Browser.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 package com.stoutner.privacybrowser.activities;
  21
  22 import android.Manifest;
  23 import android.app.Activity;
  24 import android.content.Intent;
  25 import android.content.pm.PackageManager;
  26 import android.media.MediaScannerConnection;
  27 import android.net.Uri;
  28 import android.os.Build;
  29 import android.os.Bundle;
  30 import android.os.Environment;
  31 import android.provider.DocumentsContract;
  32 import android.support.annotation.NonNull;
  33 import android.support.design.widget.Snackbar;
  34 import android.support.design.widget.TextInputLayout;
  35 import android.support.v4.app.ActivityCompat;
  36 import android.support.v4.app.DialogFragment;
  37 import android.support.v4.content.ContextCompat;
  38 import android.support.v4.content.FileProvider;
  39 import android.support.v7.app.ActionBar;
  40 import android.support.v7.app.AppCompatActivity;
  41 import android.support.v7.widget.CardView;
  42 import android.support.v7.widget.Toolbar;
  43 import android.text.Editable;
  44 import android.text.TextWatcher;
  45 import android.view.View;
  46 import android.view.WindowManager;
  47 import android.widget.AdapterView;
  48 import android.widget.ArrayAdapter;
  49 import android.widget.Button;
  50 import android.widget.EditText;
  51 import android.widget.LinearLayout;
  52 import android.widget.RadioButton;
  53 import android.widget.Spinner;
  54 import android.widget.TextView;
  55
  56 import com.stoutner.privacybrowser.R;
  57 import com.stoutner.privacybrowser.dialogs.StoragePermissionDialog;
  58 import com.stoutner.privacybrowser.helpers.ImportExportDatabaseHelper;
  59
  60 import java.io.File;
  61 import java.io.FileInputStream;
  62 import java.io.FileOutputStream;
  63 import java.nio.charset.StandardCharsets;
  64 import java.security.MessageDigest;
  65 import java.security.SecureRandom;
  66 import java.util.Arrays;
  67
  68 import javax.crypto.Cipher;
  69 import javax.crypto.CipherInputStream;
  70 import javax.crypto.CipherOutputStream;
  71 import javax.crypto.spec.GCMParameterSpec;
  72 import javax.crypto.spec.SecretKeySpec;
  73
  74 public class ImportExportActivity extends AppCompatActivity implements StoragePermissionDialog.StoragePermissionDialogListener {
  75     // Create the encryption constants.
  76     private final int NO_ENCRYPTION = 0;
  77     private final int PASSWORD_ENCRYPTION = 1;
  78     private final int OPENPGP_ENCRYPTION = 2;
  79
  80     // Create the activity result constants.
  81     private final int BROWSE_RESULT_CODE = 0;
  82     private final int OPENPGP_EXPORT_RESULT_CODE = 1;
  83
  84     // `openKeychainInstalled` is accessed from an inner class.
  85     private boolean openKeychainInstalled;
  86
  87     @Override
  88     public void onCreate(Bundle savedInstanceState) {
  89         // Disable screenshots if not allowed.
  90         if (!MainWebViewActivity.allowScreenshots) {
  91             getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);
  92         }
  93
  94         // Set the activity theme.
  95         if (MainWebViewActivity.darkTheme) {
  96             setTheme(R.style.PrivacyBrowserDark_SecondaryActivity);
  97         } else {
  98             setTheme(R.style.PrivacyBrowserLight_SecondaryActivity);
  99         }
 100
 101         // Run the default commands.
 102         super.onCreate(savedInstanceState);
 103
 104         // Set the content view.
 105         setContentView(R.layout.import_export_coordinatorlayout);
 106
 107         // Use the `SupportActionBar` from `android.support.v7.app.ActionBar` until the minimum API is >= 21.
 108         Toolbar importExportAppBar = findViewById(R.id.import_export_toolbar);
 109         setSupportActionBar(importExportAppBar);
 110
 111         // Display the home arrow on the support action bar.
 112         ActionBar appBar = getSupportActionBar();
 113         assert appBar != null;// This assert removes the incorrect warning in Android Studio on the following line that `appBar` might be null.
 114         appBar.setDisplayHomeAsUpEnabled(true);
 115
 116         // Find out if we are running KitKat
 117         boolean runningKitKat = (Build.VERSION.SDK_INT == 19);
 118
 119         // Find out if OpenKeychain is installed.
 120         try {
 121             openKeychainInstalled = !getPackageManager().getPackageInfo("org.sufficientlysecure.keychain", 0).versionName.isEmpty();
 122         } catch (PackageManager.NameNotFoundException exception) {
 123             openKeychainInstalled = false;
 124         }
 125
 126         // Get handles for the views that need to be modified.
 127         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 128         TextInputLayout passwordEncryptionTextInputLayout = findViewById(R.id.password_encryption_textinputlayout);
 129         EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 130         TextView kitKatPasswordEncryptionTextView = findViewById(R.id.kitkat_password_encryption_textview);
 131         TextView openKeychainRequiredTextView = findViewById(R.id.openkeychain_required_textview);
 132         CardView fileLocationCardView = findViewById(R.id.file_location_cardview);
 133         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 134         RadioButton exportRadioButton = findViewById(R.id.export_radiobutton);
 135         LinearLayout fileNameLinearLayout = findViewById(R.id.file_name_linearlayout);
 136         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 137         TextView openKeychainImportInstructionsTextView = findViewById(R.id.openkeychain_import_instructions_textview);
 138         Button importExportButton = findViewById(R.id.import_export_button);
 139         TextView storagePermissionTextView = findViewById(R.id.import_export_storage_permission_textview);
 140
 141         // Create an array adapter for the spinner.
 142         ArrayAdapter<CharSequence> encryptionArrayAdapter = ArrayAdapter.createFromResource(this, R.array.encryption_type, R.layout.spinner_item);
 143
 144         // Set the drop down view resource on the spinner.
 145         encryptionArrayAdapter.setDropDownViewResource(R.layout.spinner_dropdown_items);
 146
 147         // Set the array adapter for the spinner.
 148         encryptionSpinner.setAdapter(encryptionArrayAdapter);
 149
 150         // Initially hide the unneeded views.
 151         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 152         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 153         openKeychainRequiredTextView.setVisibility(View.GONE);
 154         fileNameLinearLayout.setVisibility(View.GONE);
 155         openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 156         importExportButton.setVisibility(View.GONE);
 157
 158         // Create strings for the default file paths.
 159         String defaultFilePath;
 160         String defaultPasswordEncryptionFilePath;
 161
 162         // Set the default file paths according to the storage permission status.
 163         if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // The storage permission has been granted.
 164             // Set the default file paths to use the external public directory.
 165             defaultFilePath = Environment.getExternalStorageDirectory() + "/" + getString(R.string.privacy_browser_settings_pbs);
 166             defaultPasswordEncryptionFilePath = defaultFilePath + ".aes";
 167         } else {  // The storage permission has not been granted.
 168             // Set the default file paths to use the external private directory.
 169             defaultFilePath = getApplicationContext().getExternalFilesDir(null) + "/" + getString(R.string.privacy_browser_settings_pbs);
 170             defaultPasswordEncryptionFilePath = defaultFilePath + ".aes";
 171         }
 172
 173         // Set the default file path.
 174         fileNameEditText.setText(defaultFilePath);
 175
 176         // Display the encryption information when the spinner changes.
 177         encryptionSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
 178             @Override
 179             public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
 180                 switch (position) {
 181                     case NO_ENCRYPTION:
 182                         // Hide the unneeded layout items.
 183                         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 184                         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 185                         openKeychainRequiredTextView.setVisibility(View.GONE);
 186                         openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 187
 188                         // Show the file location card.
 189                         fileLocationCardView.setVisibility(View.VISIBLE);
 190
 191                         // Show the file name linear layout if either import or export is checked.
 192                         if (importRadioButton.isChecked() || exportRadioButton.isChecked()) {
 193                             fileNameLinearLayout.setVisibility(View.VISIBLE);
 194                         }
 195
 196                         // Reset the text of the import button, which may have been changed to `Decrypt`.
 197                         if (importRadioButton.isChecked()) {
 198                             importExportButton.setText(R.string.import_button);
 199                         }
 200
 201                         // Reset the default file path.
 202                         fileNameEditText.setText(defaultFilePath);
 203
 204                         // Enable the import/export button if a file name exists.
 205                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 206                         break;
 207
 208                     case PASSWORD_ENCRYPTION:
 209                         if (runningKitKat) {
 210                             // Show the KitKat password encryption message.
 211                             kitKatPasswordEncryptionTextView.setVisibility(View.VISIBLE);
 212
 213                             // Hide the OpenPGP required text view and the file location card.
 214                             openKeychainRequiredTextView.setVisibility(View.GONE);
 215                             fileLocationCardView.setVisibility(View.GONE);
 216                         } else {
 217                             // Hide the OpenPGP layout items.
 218                             openKeychainRequiredTextView.setVisibility(View.GONE);
 219                             openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 220
 221                             // Show the password encryption layout items.
 222                             passwordEncryptionTextInputLayout.setVisibility(View.VISIBLE);
 223
 224                             // Show the file location card.
 225                             fileLocationCardView.setVisibility(View.VISIBLE);
 226
 227                             // Show the file name linear layout if either import or export is checked.
 228                             if (importRadioButton.isChecked() || exportRadioButton.isChecked()) {
 229                                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 230                             }
 231
 232                             // Reset the text of the import button, which may have been changed to `Decrypt`.
 233                             if (importRadioButton.isChecked()) {
 234                                 importExportButton.setText(R.string.import_button);
 235                             }
 236
 237                             // Update the default file path.
 238                             fileNameEditText.setText(defaultPasswordEncryptionFilePath);
 239
 240                             // Enable the import/export button if a password exists.
 241                             importExportButton.setEnabled(!encryptionPasswordEditText.getText().toString().isEmpty());
 242                         }
 243                         break;
 244
 245                     case OPENPGP_ENCRYPTION:
 246                         // Hide the password encryption layout items.
 247                         passwordEncryptionTextInputLayout.setVisibility(View.GONE);
 248                         kitKatPasswordEncryptionTextView.setVisibility(View.GONE);
 249
 250                         // Updated items based on the installation status of OpenKeychain.
 251                         if (openKeychainInstalled) {  // OpenKeychain is installed.
 252                             // Remove the default file path.
 253                             fileNameEditText.setText("");
 254
 255                             // Show the file location card.
 256                             fileLocationCardView.setVisibility(View.VISIBLE);
 257
 258                             if (importRadioButton.isChecked()) {
 259                                 // Show the file name linear layout and the OpenKeychain import instructions.
 260                                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 261                                 openKeychainImportInstructionsTextView.setVisibility(View.VISIBLE);
 262
 263                                 // Set the text of the import button to be `Decrypt`.
 264                                 importExportButton.setText(R.string.decrypt);
 265
 266                                 // Disable the import/export button.  The user needs to select a file to import first.
 267                                 importExportButton.setEnabled(false);
 268                             } else if (exportRadioButton.isChecked()) {
 269                                 // Hide the file name linear layout and the OpenKeychain import instructions.
 270                                 fileNameLinearLayout.setVisibility(View.GONE);
 271                                 openKeychainImportInstructionsTextView.setVisibility(View.GONE);
 272
 273                                 // Enable the import/export button.
 274                                 importExportButton.setEnabled(true);
 275                             }
 276                         } else {  // OpenKeychain is not installed.
 277                             // Show the OpenPGP required layout item.
 278                             openKeychainRequiredTextView.setVisibility(View.VISIBLE);
 279
 280                             // Hide the file location card.
 281                             fileLocationCardView.setVisibility(View.GONE);
 282                         }
 283                         break;
 284                 }
 285             }
 286
 287             @Override
 288             public void onNothingSelected(AdapterView<?> parent) {
 289
 290             }
 291         });
 292
 293         // Update the status of the import/export button when the password changes.
 294         encryptionPasswordEditText.addTextChangedListener(new TextWatcher() {
 295             @Override
 296             public void beforeTextChanged(CharSequence s, int start, int count, int after) {
 297                 // Do nothing.
 298             }
 299
 300             @Override
 301             public void onTextChanged(CharSequence s, int start, int before, int count) {
 302                 // Do nothing.
 303             }
 304
 305             @Override
 306             public void afterTextChanged(Editable s) {
 307                 // Enable the import/export button if a file name and password exists.
 308                 importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty() && !encryptionPasswordEditText.getText().toString().isEmpty());
 309             }
 310         });
 311
 312         // Update the status of the import/export button when the file name EditText changes.
 313         fileNameEditText.addTextChangedListener(new TextWatcher() {
 314             @Override
 315             public void beforeTextChanged(CharSequence s, int start, int count, int after) {
 316                 // Do nothing.
 317             }
 318
 319             @Override
 320             public void onTextChanged(CharSequence s, int start, int before, int count) {
 321                 // Do nothing.
 322             }
 323
 324             @Override
 325             public void afterTextChanged(Editable s) {
 326                 // Adjust the export button according to the encryption spinner position.
 327                 switch (encryptionSpinner.getSelectedItemPosition()) {
 328                     case NO_ENCRYPTION:
 329                         // Enable the import/export button if a file name exists.
 330                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 331                         break;
 332
 333                     case PASSWORD_ENCRYPTION:
 334                         // Enable the import/export button if a file name and password exists.
 335                         importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty() && !encryptionPasswordEditText.getText().toString().isEmpty());
 336                         break;
 337
 338                     case OPENPGP_ENCRYPTION:
 339                         // Enable the import/export button if OpenKeychain is installed and a file name exists.
 340                         importExportButton.setEnabled(openKeychainInstalled && !fileNameEditText.getText().toString().isEmpty());
 341                         break;
 342                 }
 343             }
 344         });
 345
 346         // Hide the storage permissions text view on API < 23 as permissions on older devices are automatically granted.
 347         if (Build.VERSION.SDK_INT < 23) {
 348             storagePermissionTextView.setVisibility(View.GONE);
 349         }
 350     }
 351
 352     public void onClickRadioButton(View view) {
 353         // Get handles for the views.
 354         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 355         LinearLayout fileNameLinearLayout = findViewById(R.id.file_name_linearlayout);
 356         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 357         TextView openKeychainImportInstructionTextView = findViewById(R.id.openkeychain_import_instructions_textview);
 358         Button importExportButton = findViewById(R.id.import_export_button);
 359
 360         // Check to see if import or export was selected.
 361         switch (view.getId()) {
 362             case R.id.import_radiobutton:
 363                 // Check to see if OpenPGP encryption is selected.
 364                 if (encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) {  // OpenPGP encryption selected.
 365                     // Show the OpenKeychain import instructions.
 366                     openKeychainImportInstructionTextView.setVisibility(View.VISIBLE);
 367
 368                     // Set the text on the import/export button to be `Decrypt`.
 369                     importExportButton.setText(R.string.decrypt);
 370
 371                     // Enable the decrypt button if there is a file name.
 372                     importExportButton.setEnabled(!fileNameEditText.getText().toString().isEmpty());
 373                 } else {  // OpenPGP encryption not selected.
 374                     // Hide the OpenKeychain import instructions.
 375                     openKeychainImportInstructionTextView.setVisibility(View.GONE);
 376
 377                     // Set the text on the import/export button to be `Import`.
 378                     importExportButton.setText(R.string.import_button);
 379                 }
 380
 381                 // Display the file name views.
 382                 fileNameLinearLayout.setVisibility(View.VISIBLE);
 383                 importExportButton.setVisibility(View.VISIBLE);
 384                 break;
 385
 386             case R.id.export_radiobutton:
 387                 // Hide the OpenKeychain import instructions.
 388                 openKeychainImportInstructionTextView.setVisibility(View.GONE);
 389
 390                 // Set the text on the import/export button to be `Export`.
 391                 importExportButton.setText(R.string.export);
 392
 393                 // Show the import/export button.
 394                 importExportButton.setVisibility(View.VISIBLE);
 395
 396                 // Check to see if OpenPGP encryption is selected.
 397                 if (encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) {  // OpenPGP encryption is selected.
 398                     // Hide the file name views.
 399                     fileNameLinearLayout.setVisibility(View.GONE);
 400
 401                     // Enable the export button.
 402                     importExportButton.setEnabled(true);
 403                 } else {  // OpenPGP encryption is not selected.
 404                     // Show the file name views.
 405                     fileNameLinearLayout.setVisibility(View.VISIBLE);
 406                 }
 407                 break;
 408         }
 409     }
 410
 411     public void browse(View view) {
 412         // Get a handle for the import radiobutton.
 413         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 414
 415         // Check to see if import or export is selected.
 416         if (importRadioButton.isChecked()) {  // Import is selected.
 417             // Create the file picker intent.
 418             Intent importBrowseIntent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
 419
 420             // Set the intent MIME type to include all files so that everything is visible.
 421             importBrowseIntent.setType("*/*");
 422
 423             // Set the initial directory if the minimum API >= 26.
 424             if (Build.VERSION.SDK_INT >= 26) {
 425                 importBrowseIntent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, Environment.getExternalStorageDirectory());
 426             }
 427
 428             // Request a file that can be opened.
 429             importBrowseIntent.addCategory(Intent.CATEGORY_OPENABLE);
 430
 431             // Launch the file picker.
 432             startActivityForResult(importBrowseIntent, BROWSE_RESULT_CODE);
 433         } else {  // Export is selected
 434             // Create the file picker intent.
 435             Intent exportBrowseIntent = new Intent(Intent.ACTION_CREATE_DOCUMENT);
 436
 437             // Set the intent MIME type to include all files so that everything is visible.
 438             exportBrowseIntent.setType("*/*");
 439
 440             // Set the initial export file name.
 441             exportBrowseIntent.putExtra(Intent.EXTRA_TITLE, getString(R.string.privacy_browser_settings_pbs));
 442
 443             // Set the initial directory if the minimum API >= 26.
 444             if (Build.VERSION.SDK_INT >= 26) {
 445                 exportBrowseIntent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, Environment.getExternalStorageDirectory());
 446             }
 447
 448             // Request a file that can be opened.
 449             exportBrowseIntent.addCategory(Intent.CATEGORY_OPENABLE);
 450
 451             // Launch the file picker.
 452             startActivityForResult(exportBrowseIntent, BROWSE_RESULT_CODE);
 453         }
 454     }
 455
 456     public void importExport(View view) {
 457         // Get a handle for the views.
 458         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 459         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 460         RadioButton exportRadioButton = findViewById(R.id.export_radiobutton);
 461
 462         // Check to see if the storage permission is needed.
 463         if ((encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION) && exportRadioButton.isChecked()) {  // Permission not needed to export via OpenKeychain.
 464             // Export the settings.
 465             exportSettings();
 466         } else if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {  // The storage permission has been granted.
 467             // Check to see if import or export is selected.
 468             if (importRadioButton.isChecked()) {  // Import is selected.
 469                 // Import the settings.
 470                 importSettings();
 471             } else {  // Export is selected.
 472                 // Export the settings.
 473                 exportSettings();
 474             }
 475         } else {  // The storage permission has not been granted.
 476             // Get a handle for the file name EditText.
 477             EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 478
 479             // Get the file name string.
 480             String fileNameString = fileNameEditText.getText().toString();
 481
 482             // Get the external private directory `File`.
 483             File externalPrivateDirectoryFile = getExternalFilesDir(null);
 484
 485             // Remove the incorrect lint error below that the file might be null.
 486             assert externalPrivateDirectoryFile != null;
 487
 488             // Get the external private directory string.
 489             String externalPrivateDirectory = externalPrivateDirectoryFile.toString();
 490
 491             // Check to see if the file path is in the external private directory.
 492             if (fileNameString.startsWith(externalPrivateDirectory)) {  // The file path is in the external private directory.
 493                 // Check to see if import or export is selected.
 494                 if (importRadioButton.isChecked()) {  // Import is selected.
 495                     // Import the settings.
 496                     importSettings();
 497                 } else {  // Export is selected.
 498                     // Export the settings.
 499                     exportSettings();
 500                 }
 501             } else {  // The file path is in a public directory.
 502                 // Check if the user has previously denied the storage permission.
 503                 if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {  // Show a dialog explaining the request first.
 504                     // Instantiate the storage permission alert dialog.
 505                     DialogFragment storagePermissionDialogFragment = new StoragePermissionDialog();
 506
 507                     // Show the storage permission alert dialog.  The permission will be requested when the dialog is closed.
 508                     storagePermissionDialogFragment.show(getSupportFragmentManager(), getString(R.string.storage_permission));
 509                 } else {  // Show the permission request directly.
 510                     // Request the storage permission.  The export will be run when it finishes.
 511                     ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, 0);
 512                 }
 513             }
 514         }
 515     }
 516
 517     @Override
 518     public void onCloseStoragePermissionDialog() {
 519         // Request the write external storage permission.  The import/export will be run when it finishes.
 520         ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, 0);
 521     }
 522
 523     @Override
 524     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
 525         // Get a handle for the import radiobutton.
 526         RadioButton importRadioButton = findViewById(R.id.import_radiobutton);
 527
 528         // Check to see if the storage permission was granted.  If the dialog was canceled the grant results will be empty.
 529         if ((grantResults.length > 0) && (grantResults[0] == PackageManager.PERMISSION_GRANTED)) {  // The storage permission was granted.
 530             // Run the import or export methods according to which radio button is selected.
 531             if (importRadioButton.isChecked()) {  // Import is selected.
 532                 // Import the settings.
 533                 importSettings();
 534             } else {  // Export is selected.
 535                 // Export the settings.
 536                 exportSettings();
 537             }
 538         } else {  // The storage permission was not granted.
 539             // Display an error snackbar.
 540             Snackbar.make(importRadioButton, getString(R.string.cannot_use_location), Snackbar.LENGTH_LONG).show();
 541         }
 542     }
 543
 544     @Override
 545     public void onActivityResult(int requestCode, int resultCode, Intent data) {
 546         switch (requestCode) {
 547             case (BROWSE_RESULT_CODE):
 548                 // Don't do anything if the user pressed back from the file picker.
 549                 if (resultCode == Activity.RESULT_OK) {
 550                     // Get a handle for the file name edit text.
 551                     EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 552
 553                     // Get the file name URI.
 554                     Uri fileNameUri = data.getData();
 555
 556                     // Remove the lint warning that the file name URI might be null.
 557                     assert fileNameUri != null;
 558
 559                     // Get the raw file name path.
 560                     String rawFileNamePath = fileNameUri.getPath();
 561
 562                     // Remove the incorrect lint warning that the file name path might be null.
 563                     assert rawFileNamePath != null;
 564
 565                     // Check to see if the file name Path includes a valid storage location.
 566                     if (rawFileNamePath.contains(":")) {  // The path is valid.
 567                         // Split the path into the initial content uri and the final path information.
 568                         String fileNameContentPath = rawFileNamePath.substring(0, rawFileNamePath.indexOf(":"));
 569                         String fileNameFinalPath = rawFileNamePath.substring(rawFileNamePath.indexOf(":") + 1);
 570
 571                         // Create the file name path string.
 572                         String fileNamePath;
 573
 574                         // Construct the file name path.
 575                         switch (fileNameContentPath) {
 576                             // The documents home has a special content path.
 577                             case "/document/home":
 578                                 fileNamePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS) + "/" + fileNameFinalPath;
 579                                 break;
 580
 581                             // Everything else for the primary user should be in `/document/primary`.
 582                             case "/document/primary":
 583                                 fileNamePath = Environment.getExternalStorageDirectory() + "/" + fileNameFinalPath;
 584                                 break;
 585
 586                             // Just in case, catch everything else and place it in the external storage directory.
 587                             default:
 588                                 fileNamePath = Environment.getExternalStorageDirectory() + "/" + fileNameFinalPath;
 589                                 break;
 590                         }
 591
 592                         // Set the file name path as the text of the file name EditText.
 593                         fileNameEditText.setText(fileNamePath);
 594                     } else {  // The path is invalid.
 595                         Snackbar.make(fileNameEditText, rawFileNamePath + " " + getString(R.string.invalid_location), Snackbar.LENGTH_INDEFINITE).show();
 596                     }
 597                 }
 598                 break;
 599
 600             case OPENPGP_EXPORT_RESULT_CODE:
 601                 // Get the temporary unencrypted export file.
 602                 File temporaryUnencryptedExportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.privacy_browser_settings_pbs));
 603
 604                 // Delete the temporary unencrypted export file if it exists.
 605                 if (temporaryUnencryptedExportFile.exists()) {
 606                     //noinspection ResultOfMethodCallIgnored
 607                     temporaryUnencryptedExportFile.delete();
 608                 }
 609                 break;
 610         }
 611     }
 612
 613     private void exportSettings() {
 614         // Get a handle for the views.
 615         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 616         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 617
 618         // Instantiate the import export database helper.
 619         ImportExportDatabaseHelper importExportDatabaseHelper = new ImportExportDatabaseHelper();
 620
 621         // Get the export file string.
 622         String exportFileString = fileNameEditText.getText().toString();
 623
 624         // Get the export and temporary unencrypted export files.
 625         File exportFile = new File(exportFileString);
 626         File temporaryUnencryptedExportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.privacy_browser_settings_pbs));
 627
 628         // Create an export status string.
 629         String exportStatus;
 630
 631         // Export according to the encryption type.
 632         switch (encryptionSpinner.getSelectedItemPosition()) {
 633             case NO_ENCRYPTION:
 634                 // Export the unencrypted file.
 635                 exportStatus = importExportDatabaseHelper.exportUnencrypted(exportFile, this);
 636
 637                 // Show a disposition snackbar.
 638                 if (exportStatus.equals(ImportExportDatabaseHelper.EXPORT_SUCCESSFUL)) {
 639                     Snackbar.make(fileNameEditText, getString(R.string.export_successful), Snackbar.LENGTH_SHORT).show();
 640                 } else {
 641                     Snackbar.make(fileNameEditText, getString(R.string.export_failed) + "  " + exportStatus, Snackbar.LENGTH_INDEFINITE).show();
 642                 }
 643                 break;
 644
 645             case PASSWORD_ENCRYPTION:
 646                 // Create an unencrypted export in a private directory.
 647                 exportStatus = importExportDatabaseHelper.exportUnencrypted(temporaryUnencryptedExportFile, this);
 648
 649                 try {
 650                     // Create an unencrypted export file input stream.
 651                     FileInputStream unencryptedExportFileInputStream = new FileInputStream(temporaryUnencryptedExportFile);
 652
 653                     // Delete the encrypted export file if it exists.
 654                     if (exportFile.exists()) {
 655                         //noinspection ResultOfMethodCallIgnored
 656                         exportFile.delete();
 657                     }
 658
 659                     // Create an encrypted export file output stream.
 660                     FileOutputStream encryptedExportFileOutputStream = new FileOutputStream(exportFile);
 661
 662                     // Get a handle for the encryption password EditText.
 663                     EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 664
 665                     // Get the encryption password.
 666                     String encryptionPasswordString = encryptionPasswordEditText.getText().toString();
 667
 668                     // Initialize a secure random number generator.
 669                     SecureRandom secureRandom = new SecureRandom();
 670
 671                     // Get a 256 bit (32 byte) random salt.
 672                     byte[] saltByteArray = new byte[32];
 673                     secureRandom.nextBytes(saltByteArray);
 674
 675                     // Convert the encryption password to a byte array.
 676                     byte[] encryptionPasswordByteArray = encryptionPasswordString.getBytes(StandardCharsets.UTF_8);
 677
 678                     // Append the salt to the encryption password byte array.  This protects against rainbow table attacks.
 679                     byte[] encryptionPasswordWithSaltByteArray = new byte[encryptionPasswordByteArray.length + saltByteArray.length];
 680                     System.arraycopy(encryptionPasswordByteArray, 0, encryptionPasswordWithSaltByteArray, 0, encryptionPasswordByteArray.length);
 681                     System.arraycopy(saltByteArray, 0, encryptionPasswordWithSaltByteArray, encryptionPasswordByteArray.length, saltByteArray.length);
 682
 683                     // Get a SHA-512 message digest.
 684                     MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");
 685
 686                     // Hash the salted encryption password.  Otherwise, any characters after the 32nd character in the password are ignored.
 687                     byte[] hashedEncryptionPasswordWithSaltByteArray = messageDigest.digest(encryptionPasswordWithSaltByteArray);
 688
 689                     // Truncate the encryption password byte array to 256 bits (32 bytes).
 690                     byte[] truncatedHashedEncryptionPasswordWithSaltByteArray = Arrays.copyOf(hashedEncryptionPasswordWithSaltByteArray, 32);
 691
 692                     // Create an AES secret key from the encryption password byte array.
 693                     SecretKeySpec secretKey = new SecretKeySpec(truncatedHashedEncryptionPasswordWithSaltByteArray, "AES");
 694
 695                     // Generate a random 12 byte initialization vector.  According to NIST, a 12 byte initialization vector is more secure than a 16 byte one.
 696                     byte[] initializationVector = new byte[12];
 697                     secureRandom.nextBytes(initializationVector);
 698
 699                     // Get a Advanced Encryption Standard, Galois/Counter Mode, No Padding cipher instance. Galois/Counter mode protects against modification of the ciphertext.  It doesn't use padding.
 700                     Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
 701
 702                     // Set the GCM tag length to be 128 bits (the maximum) and apply the initialization vector.
 703                     GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(128, initializationVector);
 704
 705                     // Initialize the cipher.
 706                     cipher.init(Cipher.ENCRYPT_MODE, secretKey, gcmParameterSpec);
 707
 708                     // Add the salt and the initialization vector to the export file.
 709                     encryptedExportFileOutputStream.write(saltByteArray);
 710                     encryptedExportFileOutputStream.write(initializationVector);
 711
 712                     // Create a cipher output stream.
 713                     CipherOutputStream cipherOutputStream = new CipherOutputStream(encryptedExportFileOutputStream, cipher);
 714
 715                     // Initialize variables to store data as it is moved from the unencrypted export file input stream to the cipher output stream.  Move 128 bits (16 bytes) at a time.
 716                     int numberOfBytesRead;
 717                     byte[] encryptedBytes = new byte[16];
 718
 719                     // Read up to 128 bits (16 bytes) of data from the unencrypted export file stream.  `-1` will be returned when the end of the file is reached.
 720                     while ((numberOfBytesRead = unencryptedExportFileInputStream.read(encryptedBytes)) != -1) {
 721                         // Write the data to the cipher output stream.
 722                         cipherOutputStream.write(encryptedBytes, 0, numberOfBytesRead);
 723                     }
 724
 725                     // Close the streams.
 726                     cipherOutputStream.flush();
 727                     cipherOutputStream.close();
 728                     encryptedExportFileOutputStream.close();
 729                     unencryptedExportFileInputStream.close();
 730
 731                     // Wipe the encryption data from memory.
 732                     //noinspection UnusedAssignment
 733                     encryptionPasswordString = "";
 734                     Arrays.fill(saltByteArray, (byte) 0);
 735                     Arrays.fill(encryptionPasswordByteArray, (byte) 0);
 736                     Arrays.fill(encryptionPasswordWithSaltByteArray, (byte) 0);
 737                     Arrays.fill(hashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 738                     Arrays.fill(truncatedHashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 739                     Arrays.fill(initializationVector, (byte) 0);
 740                     Arrays.fill(encryptedBytes, (byte) 0);
 741
 742                     // Delete the temporary unencrypted export file.
 743                     //noinspection ResultOfMethodCallIgnored
 744                     temporaryUnencryptedExportFile.delete();
 745                 } catch (Exception exception) {
 746                     exportStatus = exception.toString();
 747                 }
 748
 749                 // Show a disposition snackbar.
 750                 if (exportStatus.equals(ImportExportDatabaseHelper.EXPORT_SUCCESSFUL)) {
 751                     Snackbar.make(fileNameEditText, getString(R.string.export_successful), Snackbar.LENGTH_SHORT).show();
 752                 } else {
 753                     Snackbar.make(fileNameEditText, getString(R.string.export_failed) + "  " + exportStatus, Snackbar.LENGTH_INDEFINITE).show();
 754                 }
 755                 break;
 756
 757             case OPENPGP_ENCRYPTION:
 758                 // Create an unencrypted export in the private location.
 759                 importExportDatabaseHelper.exportUnencrypted(temporaryUnencryptedExportFile, this);
 760
 761                 // Create an encryption intent for OpenKeychain.
 762                 Intent openKeychainEncryptIntent = new Intent("org.sufficientlysecure.keychain.action.ENCRYPT_DATA");
 763
 764                 // Include the temporary unencrypted export file URI.
 765                 openKeychainEncryptIntent.setData(FileProvider.getUriForFile(this, getString(R.string.file_provider), temporaryUnencryptedExportFile));
 766
 767                 // Allow OpenKeychain to read the file URI.
 768                 openKeychainEncryptIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 769
 770                 // Send the intent to the OpenKeychain package.
 771                 openKeychainEncryptIntent.setPackage("org.sufficientlysecure.keychain");
 772
 773                 // Make it so.
 774                 startActivityForResult(openKeychainEncryptIntent, OPENPGP_EXPORT_RESULT_CODE);
 775                 break;
 776         }
 777
 778         // Add the file to the list of recent files.  This doesn't currently work, but maybe it will someday.
 779         MediaScannerConnection.scanFile(this, new String[] {exportFileString}, new String[] {"application/x-sqlite3"}, null);
 780     }
 781
 782     private void importSettings() {
 783         // Get a handle for the views.
 784         Spinner encryptionSpinner = findViewById(R.id.encryption_spinner);
 785         EditText fileNameEditText = findViewById(R.id.file_name_edittext);
 786
 787         // Instantiate the import export database helper.
 788         ImportExportDatabaseHelper importExportDatabaseHelper = new ImportExportDatabaseHelper();
 789
 790         // Get the import file.
 791         File importFile = new File(fileNameEditText.getText().toString());
 792
 793         // Initialize the import status string
 794         String importStatus = "";
 795
 796         // Import according to the encryption type.
 797         switch (encryptionSpinner.getSelectedItemPosition()) {
 798             case NO_ENCRYPTION:
 799                 // Import the unencrypted file.
 800                 importStatus = importExportDatabaseHelper.importUnencrypted(importFile, this);
 801                 break;
 802
 803             case PASSWORD_ENCRYPTION:
 804                 // Use a private temporary import location.
 805                 File temporaryUnencryptedImportFile = new File(getApplicationContext().getCacheDir() + "/" + getString(R.string.privacy_browser_settings_pbs));
 806
 807                 try {
 808                     // Create an encrypted import file input stream.
 809                     FileInputStream encryptedImportFileInputStream = new FileInputStream(importFile);
 810
 811                     // Delete the temporary import file if it exists.
 812                     if (temporaryUnencryptedImportFile.exists()) {
 813                         //noinspection ResultOfMethodCallIgnored
 814                         temporaryUnencryptedImportFile.delete();
 815                     }
 816
 817                     // Create an unencrypted import file output stream.
 818                     FileOutputStream unencryptedImportFileOutputStream = new FileOutputStream(temporaryUnencryptedImportFile);
 819
 820                     // Get a handle for the encryption password EditText.
 821                     EditText encryptionPasswordEditText = findViewById(R.id.password_encryption_edittext);
 822
 823                     // Get the encryption password.
 824                     String encryptionPasswordString = encryptionPasswordEditText.getText().toString();
 825
 826                     // Get the salt from the beginning of the import file.
 827                     byte[] saltByteArray = new byte[32];
 828                     //noinspection ResultOfMethodCallIgnored
 829                     encryptedImportFileInputStream.read(saltByteArray);
 830
 831                     // Get the initialization vector from the import file.
 832                     byte[] initializationVector = new byte[12];
 833                     //noinspection ResultOfMethodCallIgnored
 834                     encryptedImportFileInputStream.read(initializationVector);
 835
 836                     // Convert the encryption password to a byte array.
 837                     byte[] encryptionPasswordByteArray = encryptionPasswordString.getBytes(StandardCharsets.UTF_8);
 838
 839                     // Append the salt to the encryption password byte array.  This protects against rainbow table attacks.
 840                     byte[] encryptionPasswordWithSaltByteArray = new byte[encryptionPasswordByteArray.length + saltByteArray.length];
 841                     System.arraycopy(encryptionPasswordByteArray, 0, encryptionPasswordWithSaltByteArray, 0, encryptionPasswordByteArray.length);
 842                     System.arraycopy(saltByteArray, 0, encryptionPasswordWithSaltByteArray, encryptionPasswordByteArray.length, saltByteArray.length);
 843
 844                     // Get a SHA-512 message digest.
 845                     MessageDigest messageDigest = MessageDigest.getInstance("SHA-512");
 846
 847                     // Hash the salted encryption password.  Otherwise, any characters after the 32nd character in the password are ignored.
 848                     byte[] hashedEncryptionPasswordWithSaltByteArray = messageDigest.digest(encryptionPasswordWithSaltByteArray);
 849
 850                     // Truncate the encryption password byte array to 256 bits (32 bytes).
 851                     byte[] truncatedHashedEncryptionPasswordWithSaltByteArray = Arrays.copyOf(hashedEncryptionPasswordWithSaltByteArray, 32);
 852
 853                     // Create an AES secret key from the encryption password byte array.
 854                     SecretKeySpec secretKey = new SecretKeySpec(truncatedHashedEncryptionPasswordWithSaltByteArray, "AES");
 855
 856                     // Get a Advanced Encryption Standard, Galois/Counter Mode, No Padding cipher instance. Galois/Counter mode protects against modification of the ciphertext.  It doesn't use padding.
 857                     Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
 858
 859                     // Set the GCM tag length to be 128 bits (the maximum) and apply the initialization vector.
 860                     GCMParameterSpec gcmParameterSpec = new GCMParameterSpec(128, initializationVector);
 861
 862                     // Initialize the cipher.
 863                     cipher.init(Cipher.DECRYPT_MODE, secretKey, gcmParameterSpec);
 864
 865                     // Create a cipher input stream.
 866                     CipherInputStream cipherInputStream = new CipherInputStream(encryptedImportFileInputStream, cipher);
 867
 868                     // Initialize variables to store data as it is moved from the cipher input stream to the unencrypted import file output stream.  Move 128 bits (16 bytes) at a time.
 869                     int numberOfBytesRead;
 870                     byte[] decryptedBytes = new byte[16];
 871
 872                     // Read up to 128 bits (16 bytes) of data from the cipher input stream.  `-1` will be returned when the end fo the file is reached.
 873                     while ((numberOfBytesRead = cipherInputStream.read(decryptedBytes)) != -1) {
 874                         // Write the data to the unencrypted import file output stream.
 875                         unencryptedImportFileOutputStream.write(decryptedBytes, 0, numberOfBytesRead);
 876                     }
 877
 878                     // Close the streams.
 879                     unencryptedImportFileOutputStream.flush();
 880                     unencryptedImportFileOutputStream.close();
 881                     cipherInputStream.close();
 882                     encryptedImportFileInputStream.close();
 883
 884                     // Wipe the encryption data from memory.
 885                     //noinspection UnusedAssignment
 886                     encryptionPasswordString = "";
 887                     Arrays.fill(saltByteArray, (byte) 0);
 888                     Arrays.fill(initializationVector, (byte) 0);
 889                     Arrays.fill(encryptionPasswordByteArray, (byte) 0);
 890                     Arrays.fill(encryptionPasswordWithSaltByteArray, (byte) 0);
 891                     Arrays.fill(hashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 892                     Arrays.fill(truncatedHashedEncryptionPasswordWithSaltByteArray, (byte) 0);
 893                     Arrays.fill(decryptedBytes, (byte) 0);
 894
 895                     // Import the unencrypted database from the private location.
 896                     importStatus = importExportDatabaseHelper.importUnencrypted(temporaryUnencryptedImportFile, this);
 897
 898                     // Delete the temporary unencrypted import file.
 899                     //noinspection ResultOfMethodCallIgnored
 900                     temporaryUnencryptedImportFile.delete();
 901                 } catch (Exception exception) {
 902                     importStatus = exception.toString();
 903                 }
 904                 break;
 905
 906             case OPENPGP_ENCRYPTION:
 907                 try {
 908                     // Create an decryption intent for OpenKeychain.
 909                     Intent openKeychainDecryptIntent = new Intent("org.sufficientlysecure.keychain.action.DECRYPT_DATA");
 910
 911                     // Include the URI to be decrypted.
 912                     openKeychainDecryptIntent.setData(FileProvider.getUriForFile(this, getString(R.string.file_provider), importFile));
 913
 914                     // Allow OpenKeychain to read the file URI.
 915                     openKeychainDecryptIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 916
 917                     // Send the intent to the OpenKeychain package.
 918                     openKeychainDecryptIntent.setPackage("org.sufficientlysecure.keychain");
 919
 920                     // Make it so.
 921                     startActivity(openKeychainDecryptIntent);
 922                 } catch (IllegalArgumentException exception) {  // The file import location is not valid.
 923                     // Display a snack bar with the import error.
 924                     Snackbar.make(fileNameEditText, getString(R.string.import_failed) + "  " + exception.toString(), Snackbar.LENGTH_INDEFINITE).show();
 925                 }
 926                 break;
 927         }
 928
 929         // Respond to the import disposition.
 930         if (importStatus.equals(ImportExportDatabaseHelper.IMPORT_SUCCESSFUL)) {  // The import was successful.
 931             // Create an intent to restart Privacy Browser.
 932             Intent restartIntent = getParentActivityIntent();
 933
 934             // Assert that the intent is not null to remove the lint error below.
 935             assert restartIntent != null;
 936
 937             // `Intent.FLAG_ACTIVITY_CLEAR_TASK` removes all activities from the stack.  It requires `Intent.FLAG_ACTIVITY_NEW_TASK`.
 938             restartIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
 939
 940             // Make it so.
 941             startActivity(restartIntent);
 942         } else if (!(encryptionSpinner.getSelectedItemPosition() == OPENPGP_ENCRYPTION)){  // The import was not successful.
 943             // Display a snack bar with the import error.
 944             Snackbar.make(fileNameEditText, getString(R.string.import_failed) + "  " + importStatus, Snackbar.LENGTH_INDEFINITE).show();
 945         }
 946     }
 947 }